Large corrugated containers are in widespread use today. Such containers or boxes are used to house for shipment bulky manufactured items, such as refrigerators, engines, transmissions and the like. Such containers are also in widespread use to house and ship particulate materials such as resin pellets, and such containers are commonly known in the art as "bulk bin boxes."
It is also well-known in the art to provide large corrugated containers of the type described in the preceding paragraph with a multi-ply, or multi-wall, laminated construction, at least in those portions of the container that are subjected to high stresses.
Such containers are typically formed from a prescored corrugated blank by folding the blank about the score lines to bring edge portions of sections of the blank into overlapping juxtaposed relationship, and forming a joint in the overlapped portions. Such a joint is referred to in the art as a "manufacturers joint," and is most commonly formed by applying a suitable adhesive to one or both of the overlapping blank sections.
While it has been known to form such containers by hand around the article, or articles, to be packaged; machines have been developed for automatically or semi-automatically folding a prescored corrugated blank and forming a glued manufacturer's joint therein.
So-called "folder-gluer" machines that have been developed to date have not met with widespread successful commercial use, because of a number of inherent problems associated therewith. Not the least of which problems is that such machines have tended to be extremely bulky, very costly, inconsistent and ineffective in use, and difficult and time consuming to convert from one size container to another.
Other prior art folder-gluer machines that have been used in the past are extremely labor intensive, and hence costly to operate, particularly when one considers the capital investment required for such equipment.
In one known type of folder-gluer apparatus, prescored blanks are fed past folding mechanisms, which fold the outboard blank panels about parallel score lines as the blank is conveyed past the folding mechanisms. Since the folding action with this type of equipment is accomplished progressively from one end of the blank to the other, as the blank is conveyed past the folding mechanism, difficulty is often encountered in accomplishing a square fold at the score lines, particularly when the leading edge of the blank is engaged by the folding mechanism. Non-square fold lines lead to subsequent stacking problems once the folding and gluing operation is completed.
Folding problems are also encountered with presently available high-speed equipment on heavy walled blanks, particularly multi-wall laminated blanks. Damage to the blanks and jamming of the equipment have resulted.
The method and apparatus of the present invention overcome the problems set forth above by providing a compact, relatively low cost, highly efficient folding and gluing system, which can be readily adjusted to accommodate blanks of differing size. Square folds can be consistently accomplished at high speeds with single wall and laminated blanks, with minimal labor involvement.